RM7895A RELAY MODULE
11
32-00122-01
a. Allow an additional two inches below the
RM7895 for the flame amplifier mounting.
b. Allow an optional three-inch minimum to both
sides of the RM7895 for electrical signal voltage
probes.
3.
Make sure no subbase wiring is projecting beyond
the terminal blocks. Tuck wiring in against the back
of the subbase so it does not interfere with the knife
blade terminals or bifurcated contacts.
4.
Mount the RM7895 by aligning the four L-shaped
corner guides and knife blade terminals with the
bifurcated contacts on the wiring subbase and tight-
ening the two screws securely without deforming the
plastic.
IMPORTANT:
Install the RM7895 with a plug-in motion rather
than a hinge action.
Installing ST7800 Purge Card
1.
Remove the Dust Cover, Keyboard Display Module,
Data ControlBus™ Module, or Extension Cable
Assembly.
2.
Remove the current ST7800 from the RM7895 by
pulling upward on the plastic support cover, see Fig.
7.
3.
Make sure the ST7800A selected has the desired
timing.
4.
Insert the Purge Card into the opening of the
RM7895. (Again, see Fig. 7.)
5.
Reinstall the Dust Cover, Keyboard Display Module,
Data ControlBus™ Module, or Extension Cable
Assembly onto the RM7895 and restore power to the
device.
6.
Run the burner system through at least one com-
plete cycle to verify that the system is operating as
desired.
Mounting Dust Cover
1.
Align the two interlocking ears of the Dust Cover with
the two mating slots on the RM7895, see Fig. 8.
2.
Insert the two interlocking ears into the two mating
slots, and, with a hinge action, push on the upper
corners of the Dust Cover to secure it to the
RM7895.
3.
Be sure the Dust Cover is firmly in place.
Installing Plug-in Flame Signal
Amplifier
1.
Disconnect the power supply before beginning
installation to prevent electrical shock and
equipment damage. More than one disconnect may
be involved.
2.
Align the amplifier circuit board edge connector with
the keyed receptacle on the RM7895. Ensure the
amplifier nameplate faces away from the relay mod-
ule. See Fig. 9.
3.
Push in the amplifier until the circuit board is fully
inserted into the receptacle and then push the
amplifier toward the RM7895 retaining clasp.
4.
Verify the amplifier is firmly in place.
5.
Restore power.
Perform all required checkout tests.
Installing the Flame Detector
NOTE:
Table 2 and Fig. 10 list the flame detection
systems available for use with theRM7895. Make
sure the correct combination of amplifier and
flame detector(s) is used.
Proper flame detection installation is the basis of a safe
and reliable flame safeguard installation. Refer to the
instructions packed with the flame detector and the
equipment manufacturer instructions.
Keep the flame signal leadwires as short as possible from
the flame detector to the wiring subbase. Capacitance
increases with leadwire length, reducing the signal
strength. The maximum permissible leadwire length
depends on the type of flame detector, leadwire and
conduit. The ultimate limiting factor in the flame detector
leadwire is the flame signal, see Table 8.
Fig. 6. Electrical panel installation.
Fig. 7. ST7800 Purge Card installation.
